Improvement in car-brakes



UNITED STATES PATENT OFFICE..

cnoncnn. BRYANT, on PoTTsvILLE, PENNSYLVANIA.

IMPROVEMENT'IN CAR-BRAKES.

Specification forming part of Letters Patent No. 155,491, dated September 29, 1874 application filed May 24, 1872.

To all whom it may concern:

Be it known that I, GEORGE B. BRYANT, of Pottsville, in the county of Schuylkill and State of Pennsylvania, have invented a new and Improved Gar-Brake; and I do hereby declare the following to be a full and exact description of the same, reference being had to the accompanying drawings, forming part of this specification, in which- Figure 1 is a perspective view of my invention, and Fig. 2 a partial plan view.

Similar letters of reference in the accompanying drawings denote the same parts.

This invention relates to that class of carbrakes in which the brake-shoes are located above the wheels, and are applied by being pressed downward upon the perimeters of the same, its peculiar construction adapting it for use only upon such cars as employ fixed axles, the ends of which project beyond the wheels; and its object is to provide a brake principally for street-cars, which can be quickly and elfectually applied, which will release itself automatically when the applyingforce is removed, and in which the pressure of the brake-shoes will be so equalized as to prevent undue strain upon the axles in any particular direction. To this end, the invention consists in locating the brake-shoes upon curved spring-plates or straps above the wheels, and operating them by means of eccentrics upon a transverse shaft between each pair of wheels, which shaft has its bearings on horizontal plates extending from the outer ends of each axle to the corresponding ends of the next, the eccentrics operating to depress the curved springstraps with their shoes, while the elasticity of the same is 'suficient to raise the shoes when the pressure is removed. y

The details of construction and method of operation will be more fully described hereinafter.

A represents thecar-truck, to which are attached the independent axles B. The outer endsof the axles are connected by horizontal plates C, inside which the wheels are journaled. D represents a shaft, which extends across the truck transversely, and is journaled in lugs E, which rise from the plates C. F represents a curved spring plate or strap,

the ends of which are attached to rods G at opposite'ends of the truck. The straps F are located above the wheels, as shown, one being connected to each side of the truck. To the lower side of the plate F are attached the brake-shoes H. Between the'wheels I I the plate F is bent downward, and passes under the shaft D, where it is provided with a block, J ,e upon its upper surface. In the top of the block J is cut a curved groove, into which projects the lower perimeter of a cam, K, this latter being located on the shaft D, and pro- .vided on one side with a projecting pin, which bears upon the upper edge of the block J. L represents a cam-shaped plate, attached to the shaft D at its center, and connected by chains M to the brake-rods N N at the opposite ends of the car.

The operation of my invention will be readily understood. When thevbrakes are to be applied, the shaft D is partially rotated by winding up the chains in the usual manner. A partial revolution of the shaft and cams will besufficient to depress the central part of the curved plates F and cause the brakeshoes to bear powerfully upon the wheels. Upon releasing the chains, the elasticity of the spring-plates is sufficient to raise the shoes, forcing the shaft back to its former p0- sitiOn, and releasing the wheels.

street-cars, though it may be advantageously l i applied to others.

The depressing-force which the cam-shaft exerts on the wheels is counterbalanced on the axles by the horizontal plates C, which are of the same elasticity as the straps F, and, consequently, yield to lthe leverage of the shaft to the same extent. The power applied is thus equally divided between` the upper sides of the wheels and the ends of the axles;4

consequently, the latter are relieved of any and camshnped plate L, connected to the excessive strain from one direction. brake-rods N, substantially as described, and

Having thus described my invention, what for the purpose set forth.

I claim is- GEORGE B. BRYANT.

The curved spring-plates F, having brake- Witnesses:

shoes H H and blocks J in combination with J AMES C. SHURDY, the horizontal pla-tes C C, shaft. D, cam K, PRESTON BREARLEY. 

